Where does “самопроизвольный” come from?

самопроизвольный (Russian) comes from Russian сам, from Old East Slavic самъ, from Proto-Slavic samъ, from Proto-Balto-Slavic *sāmas, from Proto-Indo-European somHós, from Proto-Indo-European sem- — together, one.

самопроизвольный (Russian): spontaneous

Definitions

  1. spontaneous

Ancestry of “самопроизвольный”, step by step

самопроизвольный traces back through two separate lines of ancestry.

via Russian сам

StepLanguageWordMeaning
1Russianсамself, -self
2Old East Slavicсамъself, oneself, alone
3Proto-Slavicsamъself, oneself
4Proto-Balto-Slavic*sāmas
5Proto-Indo-EuropeansomHóssame, alike
6Proto-Indo-Europeansem-together, one

via Russian произво́льный

StepLanguageWordMeaning
1Russianпроизво́льныйarbitrary, random, any given (determined by impulse)
2Russian-ный-ish, -ic, -al, -ed
3Old Church Slavonic-ьнъish, -ic, -al, -ed
4Proto-Slavic-ьnъ-ish, -ic, -al, -ed; From adjectives
Every word from Proto-Indo-European sem-Every word from Proto-Indo-European somHósEvery word from Proto-Balto-Slavic *sāmas